This invention relates to a method of marking the end of a yarn wound on a package and an apparatus for carrying out the method.
In the spinning of synthetic fibers, in particular in the automated spinning process it has in the past been very difficult to mark on the package the free yarn end, so as to be able to easily relocate it in the further processing. Attempts which have become known from the prior art, namely to mark, when winding an endless yarn, the end of the yarn upon completion of a winding cycle, so that it can easily be relocated, have not been satisfactory.
Known, for example, from DE-OS 1 760 243 is a method, which facilitates the relocating of the free yarn end of a cross-wound package, in that at the end of the winding cycle, a certain yarn length is wound uncrossed as a yarn reserve in the region of the head end of the cross-wound package. Although this method allows to reduce the search for the yarn end to a narrow axial section of the package, on which the yarn end is wound, the locating of the yarn, however, continues to present problems.
A method known from DE 40 23 291 A1 facilitates the locating of the yarn end of a cross-wound package in that for the formation of a yarn reserve after reaching a certain package diameter or after winding a certain amount of yarn, the yarn is guided across the package surface onto the tube, or as a secant across the end surface of the package, and subsequently returned to the package surface.
Likewise, according to the method described in DE 25 06 930 A1, a yarn reserve is formed at the end of the winding cycle. To this end, the package is removed from the takeup device and slowly rotated oppositely to the direction of winding, with the yarn end being pneumatically grasped and sucked off by a yarn suction device. Subsequently, the opening of the yarn suction device swings toward an end of the winding tube projecting from the package, whereupon the yarn is delivered to or blown by the suction device into the winding tube, or it is wound about the end of the winding tube, in that the package is again rotated in the direction of winding.
A further known method provides that, for purposes of marking the yarn end, same is tangled or interlaced with one or more previously wound layers of yarn by a blow nozzle, in particular, an entanglement nozzle which is arranged perpendicularly to the package surface and at a narrow distance therefrom.
It is the object of this invention to mark the free yarn end of a package upon completion of the winding cycle such that it is easy to relocate in the further handling of the package. In a further development of the invention, the marking of the yarn end is to occur such that same is simultaneously protected against an accidental unwinding or the like. A further object of the invention is to provide a suitable apparatus for carrying out the method.